1. Field of the Invention
This invention relates to machining of workpieces held in a precision machine vise, and more particularly, to a particular form of vise, which is of such construction as to permit the use of any of a multiplicity of replaceable quick-change head members. In one aspect of the invention, there is provided, moreover, a machine vise with a structure such that it is also possible to replace quickly and conveniently its fixed jaw member. The invention relates more particularly to apparatus of the above kind in which a changeover is made especially quick and convenient by reason of the use of a locking-pin member or means. The invention includes in its field certain method aspects with reference to the apparatus or equipment mentioned above, and in this regard, it includes particularly a method for precision-machining workpieces with the use of disposable replaceable head members associated with the movable jaw or jaws of the apparatus or equipment.
2. Description of the Prior Art
In the art of machining workpieces which are held in precision machine vise and are worked upon by means of so-called "numerical-controlled machining equipment", it has hitherto been a common practice to provide the working faces of a precision machine vise, that is, the surfaces of the vise which grasp the work, with replaceable jaw plates. These are sometimes called "soft plates", being as they are made of a metal which is somewhat softer and more machinable than the body of the metal comprising the jaws of the vise. In dealing with the making of a number of identical parts with the use of the above-mentioned numerical-control equipment, it is common practice to machine into the replaceable jaw-face plates some appropriate recesses or niches to receive a workpiece in such a way that its position is precisely known and established.
What has been said above is equally applicable, whether the precision machine vise is a one-place or a two-place vise. Those skilled in the art are aware that in the automatic or numerical control machining of workpieces, there are known (for purposes of obtaining a greater output of finished pieces per unit of time) some precision machine vises which have a central fixed member, which has the replaceable jaw plates on both sides of it, and then also first and second movable co-operating jaw members, which are themselves also then provided with replaceable jaw-plate members which grasp the work. In U.S. Pat. No. 4,529,183, there is disclosed a two-place precision machine vise of this kind. But whether the precision machine vise which is being used is of this two-place type or of the older one-place type, one of the problems facing the operator of the equipment remains essentially the same: there is a certain amount of time lost or expended in going from the machining of one kind of part (or one set of kinds of parts) to another, and most particularly, there is time lost or expended in getting properly set up again, perhaps some days or weeks later, to resume the making of one particular kind of finished workpiece. Though it is usual, in a job machine shop, to save for later use the particular replaceable jaw plates which have in them the correctly sized and positioned niches or recesses for holding the starting workpieces which are used for the making of a particular kind of finished workpiece, there is relatively frequently some difficulty about getting them correctly and accurately and securely attached to their respective jaw members so that the production of the desired kind of finished workpiece may then be resumed. Instead, too often, when the replaceable jaw plates are reinserted in the precision machine vise, they are less than "exactly right", which is the same as "not right at all"--new replaceable jaw plates will need to be made and used. The prior art has lacked any teaching of how to make a precision machine vise of the kind indicated above which contains structural features such that there are, especially in the precision machine vises that exhibit the feature of having appropriate obliquely oriented bearing surfaces as an anti-tilt or anti-cocking measure, appropriately designed jaw members which are adapted to have inserted thereon and to have removed therefrom head members to which the jaw members for contacting the workpieces may be kept securely in place. The prior art has not afforded a structure which makes it possible, simply by snapping into place a suitable set of heads and securing them with appropriate locking-pin members, to resume to making of a particular kind of desired part after a gap of some days or weeks, avoiding any chance of substantial lost time in so doing.
The prior art has also, accordingly, lacked any concept of providing a machine vise with quick-change replaceable heads which may be treated as disposable items, having work-contacting jaw faces with appropriately located niches or recesses machined thereinto. The prior art has lacked having such heads be given one, a few, or several stanzas of use, and then discarded.